An annual repack is fairly cheap if you take it to your local parachute jumping centre on a wet day when they are not dropping. IIRC it was £25 each for two parachutes.
You can watch them inspect and repack as well as trying a pull on your ripcord to see what it feels like.
On the question of whether the repack is needed every year. I have had mine done every year for 6-7 years and not found a problem. However on the 1st repack they found that one of the pins was bent and had a crack. The pin retains the ejection spring for the drogue and is under quite a lot of pressure. This could have let go uncommanded, or possibly jammed when pulled in anger.
If you keep your parachute in a dry clean environment and look after it, you would think it would be OK for more than a year, and the canopy and lines probably will be. However, don't forget that you are sitting or leaning back on it for quite a few hours per year and are moving around so can break the hardware.
It would be interesting to get real data from a packer about the "problems" they see at inspections of emergency chutes which never get used. I would expect it is in the release mechanism rather than the lines and parachute itself.