A host family is worth their weight in gold and sew-ups. Housing is not cheap in Europe, and neither are eating, rental cars, gas, or most anything else. Plus your hosts can help you out with their own connections, get you into races, and give you all kinds of assistance and advice. And while you may win some cash primes or prizes and even maybe collect limited support from your club, you'd better go prepared to foot the bill on your own. Since you asked, race winners take home from 1800 to 5000 francs in major interregional or international events.
Local races pay far, far less.
So racing in Europe won't make you rich, or even close. Chances are, you'll come home poorer, at least in a fiscal sense. As the saying goes, you never know unless you try.