IF you want a timer on a budget of $100, you have two options.. a quartz powered chronograph or an analog / digital watch. The Chrono's at this price range wont provide accurate timing as they usually just give you the minute and second.
Here's a few choices
I know some people barf at the name Invicta but they actually have some decent watches if you know your movements. This one uses a Swiss made ISA 9516/3030 quartz, which isn't bad for a $100 watch.
12470 MEN'S Invicta Intrinsic 20ATM Chrono Analog Digital Steel Diver Watch NEW | eBay
or something like this Casio and chuck on a decent leather strap.
Casio AMW320R 1EV Analog Digital Combo Black Resin Watch Alarm Stopwatch 079767850272 | eBay
or even a Fossil chrono
http://www.ebay.ca/itm/Fossil-Grant-...gFdqCs37Jl_pHQ
I hate Fossil's with a passion as the quality is horrible but it seems like what you might be looking for.