You can spend a lot or not so much, depending on what you want or need. The DTT products are considered by most members to be the "Gold Standard". The DTT TC and Valve body plus upgrades to your internals will run something over $1000+ just for parts after you return the resuable cores. In addition you can plan on $550-$800 for labor, depending on what is found when your transmission is opened up. If the internals are in good shape you will pay less, if you need major parts it will be a lot more. I did a lot of price research in recent weeks and am going to have my transmission done at the following link:
http://www.gbtransmissions.com/
This place is very good, they are TDR members and being in a tiny town in NE Iowa, don't charge an arm and a leg. Rather than tell you what they are charging me, I suggest you call Dave Goerend and discuss your needs and he will give you a quote as well as 30 or 40 minutes of very informative transmission talk. They are installing the TC and VB of their own making in my truck but will gladly install ANY product you wish to purchase and bring to the shop with you. They also think that DTT is good but maybe you have a smaller budget or don't mind slightly less efficiency for a lot less money, that's your choice...
------------------
Ron
'96 Club Cab 2500 4x4, 4:10LS, Camper/Tow package, Auto, TST 230/605, Cat Test Pipe, Cummins Chrome, Dowel pin fix, Mag-Hytec rear and trans covers, Boost, Pyro and trans gauges, Optima Red Tops, All black. Tow 14k HitchHiker triple glide 5th Wheel. Also use 9. 5' Lance camper. NRA Life Member.