Fitting Used Clubs

I need custom clubs. I am 6'3" and my wrist to floor is whatever. i have seen charts and talked to others about this and i need an inch on my irons. I have heard of extensions (i think that is what they are called) on used clubs to make them longer. I have also heard of Reshafting. I bought my father a new set and took his old set. (Old dunlops) I currently do no want to spend a lot on golf right now, so i will not buy a new set. So, would it be worth it to buy used better irons (say cleveland, TM,etc.), and get an extension on it, or just get the dunlops reshafted or extension.
Basically i am asking: 1) Which is better: extension or reshaft? 2) How much do these methods cost per club (aproximately)? 3) Will an upgrade from dunlops to a higher quality club make a real difference? 4) any websites that sell used clubs besides eBay?

Shaft extensions are cheap.

Iron Shaft Entensions If you extend the shafts when you get them re-gripped that will save you some cost since the grips will already be off the club. If you are more or less happy with the shafts that are currently on the clubs then adding 1" of length with extensions seems to make sense and is relatively easy to do. Re-shafting will cost more but makes sense if the shaft flex doesn't match your swing speed or if you just don't like the current shafts or want to change the flight characteristics of your shot. For most people who don't need a flex change and the shafts are in good shape, a re-shaft is probably not necessary. Since you don't want to spend a ton of money on your equipment right now, I'd seriously consider keeping the old irons and just having the shafts extended as long as you can hit the irons reasonably well. Re-gripping at the same time is a good idea and doesn't add much cost to the job. You'll have irons that play just like new at the right length for you then. One of the best online sites I've run across for used clubs is Global Golf . Their club ratings are very conservative, prices are reasonable and they carry good quality equipment.