Modern Vespa

I'm the reg owner. I lost my keys. Do I have any other options other than $800 one from the Scooter mechanic. He said I need the Malossi Racing CDI and then He has to take it apart and install new ignition.

Talk to AF1 Racing (you are lucky you live in Austin)

https://www.af1racing.com/ECU-Mapping-Key-Services-Gift-Certificates

I freak out every time I temporarily (so far) loose my key. I only got the one regular one and the "brown" one. I wish they would have provided two keys from new.

You can buy new key blanks and have them made to match your existing keys, and then you do through a strange little tap dance to reprogram all of them. Just lock away the brownish red key and don't use it.

on the parts you're out 200 on the CDI and 60 on a lock set.
let's be generous and say two hours of labor at 100/hr

so, 460ish? just round that up to 5 even with tax and what not.

now where's the other 300 coming from?

With the Malossi CDI, you can use the $22 lock set. It's going to be cheaper to do that than to flash the cdi and install a red/blue key set. Parts right at $200. 1.5 hours, more or less. And you have an extra tumbler. if you flash the cdi, you have more labor and down time, even if the tech can leave the bike open on his lift for a week.
By doing it this way, it's a simple on the lift, R&R the CDI and tumbler, off the lift, repair.

https://scooterpartsco.com/vespa/gt-200/gt-200-electrical/malossi-cdi-for-vespa-gt-200-other-piaggio-lc-leader

https://scooterpartsco.com/ricambi/030-piaggio/lock-and-key-set-for-vespa-piaggio-p-36596