I bought a couple straight from TriTronics, when I bought they had a turn in policy, I sent them back my ancient collar that did'nt work and I think I received 20% off, worth checking out if you have an old unit that you are upgrading.
I've been very happy with the service from gun dog supply so far.
I made a mistake on entering my address on a collar i was buying. WHen it showed up they had it corrected. I only had one letter missing, but they still fixed it. 2 business days is what it has taken to get my orders.
X4 on the collar clinic. Definitely worth your time to at least check them out and they are VERY good at standing behind anything they sell(at least they were with me when I dealt with them in the past)