Possibly buying a used Garmin 520 - Is this a good deal?

[Fookie]

Someone on my local craigslist is selling a used Garman 520 bundle without the heart strap for $150 firm. It looks like it's in good condition with only some minor scratches. It's also missing a few rubber bands , The USB charge cable , The box, the rubber shims for the ahead mount , and needs a battery replacement for both sensors.

Is this a good deal? Any advice as this will be my first bicycle computer? Thanks in advance!