Switching to another F1 chassis is fun, but do consider the cost includes getting a new set of parts. Getting a good stock of spare parts for the current RRF103 could be relatively inexpensive as compared to starting up a new car.

A suggestion is when you buy spares for your Tamiya car, store the parts bags carefully. Those parts bags, especially if in pristine condition and unopened, will be of interest to collectors on the auction sites.