Has anyone had experience with Keratin bond hair extensions?

I ordered hair extensions to be put in my hair using weaving or sewn technique. I have been looking on line and found something called a keratin bond. It is $1600 vs the $350 that I was going to pay for the sewn in extensions. I gave the stylist 250 for the hair so if I use this other (keratin bond) technique I will lose the $250. If use the other method they will surely want me to buy their hair.

I hate to lose out on the $250 and pay an extra $1300 but if I am going to do this I want it to be done well. Hopefully the upkeep on the keratin bonds isn't as expensive.??

Any one have experience with this? The price difference is huge, is it worth it?

Thanks!