Repairing/upgrading RV garage door

[MapleLeafFarmer]

I've got an RV shed with about a 12x14 sectional garage door on tracks.
When I bought the place ~ 12 years ago it was manual. No helper springs or motors. For all these years I've just lifted it up and put a 9' piece of 1x6 to hold it up. I'd spray the rollers with garage door lube when it stuck and it worked for me. Probably only opened it 50 times a year at the most,
Well, due to the expanding universe it's gotten heavier. I'd like to put on helper springs or a motor if they were affordable. Less than $500 and DIY.
Any suggestions?

if you are looking for a diy solution that easier than the spring fix a simple counter weight system on both corners is cheap and easy and relatively safe to concoct.
seems like you have been making out fine w/o so not much assist needed.