Well when I try to start my truck, it grinds really bad!! Bad enough that I think it may be hurting my flywheel.

But it is my daily driver. Well I am going today to buy a new one and was wondering which one to get. What do you guys think? Here are my options:
Duralast-limited warranty-$50 core-Price $111.99
Valucraft-1yr warranty-$65 core-Price $129.99
If it did ruin my flywheel, what am I looking at as far as price to replace that? Its a TH400. Keep in mind that the starter for my truck is heavy duty since its Diesel and 24V.