NBT – https://www.alpinresorts.com/ are usually quite competitive especially with the Snowheads discount code. I used to check out the closest v the cheapest and make a call from there. I’d never pay for the basic, but would the intermediate. I think most shops give you a ski based on what they have left over and match against your ability.
Rockape – I would say there is more choice in Briancon than the villages without the need to go to them. However, a visit for a change of scenery might be interesting. Check out the ski bus times if you don’t fancy driving it only takes a few mins to get up and down the valley. Serre Che isn’t mega lively so you don’t need to feel you might be missing out. Another option is to finish skiing in one of the villages, have a few drinks then get the bus back to Briancon.
We stayed in Villeneuve but easily managed an early evening in Briancon for a few hours after skiing (stopped at 4pm-ish) and managed to get the ski bus back. Jnr even managed to get a photo with Luc Alphand who was buying frozen pizzas in the Carrefour in Briancon.