It will be a very rare professional framebuilder that will take on an apprentice or even allow someone to hang around the shop to sweep the floor in exchange for learning opportunities. It has been shown that the ratio of benefit to effort doesn’t usually make it worthwhile.

It might be possible to rent or somehow share space with other part or full time builders. One advantage is that expensive tooling could be shared so neither has to buy everything. And spitting the cost of rent may make a tight budget possible. In Chicago there is a co-op that have a number of part and full time builders in one space for a reasonable monthly fee. They have some tools in common like an alignment table and some of their own that is off limits to others. One of the biggest challenges my frame class students face getting started after class is over is finding a place to work. That is probably a bigger issue than being able to afford adequate tooling. Sometimes they have to split where they work with a workbench at home and brazing equipment somewhere else. Garages and car ports are popular for that purpose.