if you want a motherboard for less than $100 then i suggest you change the cpu to the i7 7700 and get a b250 motherboard . that is if you don't already own the i7 7700k.
for the i7 7700k you will most likely want a z270 motherboard to allow the overclocking of the cpu .
https://www.amazon.com/dp/B01N1MOFKV/?tag=pcpapi-20 << motherboard $104 for the i7 7700k (not a recommendation just a board near to your price range)