It is not normal to buy a mixer with both functions at all. Most buy only
thermostatic mixers only.

Whatever you say.

I have bought 2 cheap thermostatic mixer showers in the last 3 years. Both
had pressure balancing operation as well as thermostatic. Each was under 100
quid. In each case, they were the cheapest thermostatic mixer valves sold by
the shop.

Christian.