Dabbling in cheese-making

When I recently bought rennet tablets to experiment with a different way of making cottage cheese, I found recipes inside the box for mozzarella cheese and a basic hard cheese similar to cheddar.  This piqued my interest, and I've read the directions several times, finally deciding to try the basic hard cheese.  One of the things required in the making of this cheese is a thermometer with a reading range from zero to two hundred twenty-five.  I don't have such a thermometer; the lowest temperature that registers on my candy thermometer is 100.  
I checked out dairy thermometers online, but at a cost of $40 (plus shipping), considering the "iffy" state of my knowledge of cheese-making, I'm not buying one.  I've been reading a Dave Ramsey book that cautions me against what he calls "stuffitis": getting "stuff" on impulse, not because you need it, but because you want it.  I've been guilty of that, and I'm trying to change.   (Thank you so much, Daily Steals, for feeding my stuffitus problem with cheap stuff.)  
After all, even if the cheese turns out great, just how often do I want to go through this process?  
Last night I was supposed to have the milk at 68 degrees, then blend in 1/4 cup of buttermilk.  This morning I'm supposed to warm it to 86 degrees and add the rennet.  I'd say the room temperature in the kitchen is at least 78, so that wouldn't take much warming.  I'm going to guess at it; after all, what do I have to lose?  I have lots of milk.  
Another concern:  I'll be using an empty twenty-ounce cherry-pie-filling can as a cheese press; like all cans, it has slight ridges encircling it.  I'm not sure how that will work when it's time to remove the cheese.  
I'm not optimistic about this project, but I'm trying it, just the same.  I'll let you know how it goes.  
Oh, by the way.  It takes at least two weeks for the cheese to get done.