HERE is the deal.
As you can see, you can buy $50 in e-gift cards (you print out and it works just like a regular gift card - no limitations) for $30. Combine that with Home Town Buffet (HTB) coupons that are ALWAYS available, and you should get at least half-off all the time. Sometimes you can even find BOGO (buy one, get one free) coupons, which would make this ... what ... like 75% off?? You can search Google for coupons and/or sign up for the email/rewards program on the HTB website - I think they send out coupons, including maybe a BOGO. And, at least at my local HTB, they always say that they don't care about expiration dates on coupons and you can bring them back and use them as often as you'd like.
If you haven't been to a HTB, it isn't as bad as you might fear. The food isn't great, but they do have some decent options (including carving station, salad, fruit & dessert - and LOTS of carbs!!). And I've observed and heard that most kids love HTB ... what's not to like about unlimited dessert?