Out of curiosity is it bad if I don't get it balanced?
If your car steers straight and your steering wheel doesn't shake or vibrate when you're driving then it should be ok.
Yeah I'd be the same, just wasn't sure if your spare was already balanced or not. $44 is quite expensive though, it should only cost around $20-$30. They just take your wheels off, put them on a rotation machine and stick some weights on them.
Where are you getting it done?
If there is no steeering wheel shake you can just leave it. It's unlikely to damage your wheel bearings but can cause uneven treead wear round the tyre if it's badly out , I have only ever seen this once though and there a tyre well out of whack was left for too long(not by me) It's a good idea to get the tracking checked once a year or so, find somewhere you believe and stick to them. You can get some idea from the front tyres, are they toed in or out from tread wear feathered on inner or outer edge of tread blocks as you would expect, aslo if the car is toed out it will not self centre.
get it balanced, you only need to do the one, an that is only if it wast balanced when you had the tyre fitted
The new tyre/wheel is the original spare - does that mean its already balanced? Or am I missing the point here?
yeah that should be fine then