Works out to about $1,450 in savings if you process $50,000. I hope people don't impulsively go with them just to take advantage of this offer. In fact, you probably don't want this offer to have anything to do with your decision-making on the best processor for your needs. That decision is not easy to undo - and will easily cost you more than the savings.
If your average cart size is $20 - that's an additional $750. $10 (Lots of Saas) it's $1,500.
Average cart size for online shopping is $110, so that's more like $150 which isn't so bad.