There are actually a few high impact polymer ones that are tougher than the budget line metal ones are.

Impact archery makes a sight called the fiber tech that is dang near bullet proof. Sells for about 45 bones.

Apex is now making a bone collector 4 pin that comes with a light and its about 60.

Tru-glo makes a 5 pin metal sight called the xtreme or something like that. Only down side is its made in taiwan or something... impacts are 100% US made. It has a light also and is around 50.. they tool less model is 55 and one that comes with a tfo pin is 60.

They are out there.

What I am going to do for this season is get an Impact NI 100... which is a fairly cheap sight for around 35 bucks. I am going to take all the pins out of it and install two Tru Glo TFO pins to set at 20 and 30 yards... the pins are worth the same as the sight is...each.... but there are no batteries to go dead and its a totally dummy proof sight. the tridium lasts for about 12 years.... just like night sights on a handgun.