Is this really a problem or is it the case that you remember and get frustrated with the one time that you can't find a space and then forget every other time that you got home and parked without any problem.
If it's only the occasional problem then I'd suggest you don't want to get into a world of paying £120 (it's what Lewisham charges where they have these schemes) to alleviate the few times that you've struggled to park outside your house.