These aren't unforeseen these are just expenses of getting set up. You'll learn like you could have saved yourself a couple of hundred buck by buying a Herpstat pro that'll run 4 rack's. Wait to buy tubs till after Christmas they go on sell.
Just some friendly advice.. Buy an extra Helix and extra Probe with winter coming and the power going on and off I've lost a helix to power surges and flickering, you don't want to get suck with a rack that is without power for 4 days waiting on a replacement thermostat. As for the probe they tend to get caught or mangled so have an extra one on hand.
Best of luck.. Now you see why people tend to get scared off their first year.. with the thousands you spend just to get started..But it's so worth it..