If this were me I'd go with Wallace. Here's my logic.

The Economy kilt is going to be or end up a "knock around" kilt. No need to get one in a tartan you will eventually want to wear later.

Blackwatch you can get virtually anywhere.

Irish National is such a unique tartan it would be ashame to get it in an economy and have to buy it again in a nicer kilt and have two of the same.

of your choices that leaves Wallace. No offense to the Wallace clan or tartan intended. You just can't get it in very many places for that price.