I have a very old soldering iron, which needs replacing. Is there any online seller that has good value-for-money soldering irons? I don't mind if it is one of the usual Chinese sellers, as far as the product is good. I am looking for 220/230V models.
Hi!
I have this station in my use:
I like it a lot and I think this is a good "cheap alternative" to Weller.
I have been using Wellers years ago at my summer time job, they were nice and I think this is not too far from them quality-wise.
I think I have read about that brand somewhere else also. I've used Weller stations also, but unfortunately they cost too much for us hobbyists... 
I have the same unit except the non digital readout version the AOYUE-936 it's $10 bucks cheaper than the 937 and I don't really need the digital readout. The AOYUE-936 is a knock off of the very expensive Japanese Hakko 936 and all the parts are interchangeable. I use the Hakko tips in mine, because they are available from KD for a couple bucks and they are better quality than the AOYUE ones. I absolutely love this iron, it is perfect for the intricate soldering on flashlight driver boards and emitters.
AOYUE-936 prices
http://sra-solder.com/product.php/6144/0
http://www.amazon.com/Aoyue-936-AOYUE-Soldering-Station/dp/B000VINMRO
Hakko tips from KD for $2.33
I just bought this station, looks to be the original HAKKO 936, 60W workstation with improved wand, although it might just be a clone underneath:
EDIT: I received the HAKKO and realized it is set for 220V with a Chinese/Australian plug. I have purchased a Step Up Voltage Converter Transformer for $9, so it turns out the HAKKO is more expensive than the Aoyue 936, but I do like the fact that it's the original and not the clone, and also that it's 60 Watts instead of 35 Watts.
It's $37.64 with free shipping (long wait!), while the Aoyue 936 is 35W and $39.99 at Amazon (free shipping if Prime member, and very short wait):
Yes, Wellers are more expensive, but think of it this way. You will have that weller for the rest of your life. In a light-use setting, a weller will never break.
I solder cables and guitar wiring all day long, 5 days a week, so I put my soldering station to a LOT of use. I have tried the digital readout solder stations, but the major problem with them is knowing whether the temperature is correct. Okay, maybe it’s correct when you first buy it, but is it correct now?
I use a Weller WTCPT. In these nifty little units, the soldering tip sets the temperature. They are right-on correct in temperature because the temp is set by the internal reistsance of the tip. You have three temperature tips: 800, 700 and 600 degrees. And probably 100 different tips for any possible use. Weller is pretty much the grandaddy of all solder stations. They are some of the safest units for soldering pcbs and delicate traces because of the grounding, or so weller says, and supposedly very ESD resistant,which you do need to be careful about.
For my general work, I use the 800 tips almost always, but they take getting used to, because at that temp you have to work FAST. Even three seconds contact with a 800-degree tip will make a pill hot enough to burn you. But the thing is, you want the solder station hot, so there is no waiting for the solder to melt because waiting for the solder to melt also transfers heat to whatever you’re soldering and will make it blisteringly hot. I can be so fast with my weller that you i can solder wires that will only be warm when finished.
Wellers are also made like tanks, but watch out for used ones as the cord from the pen to the unit does wear out after 8 million bends, maybe 10 years of continual use? And changing the wire is an absolute pain. My wires go after about 10 years. But you have to understand that this thing is used 10 hours a day, every day by me or my employees.
Not trying to sell it over other stations. Perhaps the other ones are better now. But I am really used to the wtcpt now, so I would never change. The thing about the fancy digital readout models is also to make sure that there is no lag to warm up between solderings. With the WTCPT, there is no need to wait for it to warm back up after soldering something. The thing hardly ever loses heat so you have to slow down. Maybe if you were soldering a piece o na boat or something, but PCBs and wires? Nah, you can work as fast as you can and it will never cool down from one joint to the next.
I have three in continual use now. They should be about $110 or so. Just bought one about a year ago. Just look for the cheapest well-known vendor.
And yes they do make a 240v model. Little hard to find but not impossible.
Overpriced a little maybe:
http://www.testequipmentdepot.com/weller/solder/wtcpt.htm
Hope this helps!