Some good points being raised here, and its nice to roughly know how much money is taken at a Welsh Regional and roughly how its spent. And although your minimum entry fee argument makes sense Matt, especially as you run a club & track, you can look at it another way. If the fees were slightly lower this should attract extra drivers. More drivers equals more entry fees ( albeit lower per head ) which
should cover the less drivers/higher entry fee. If that were the case, i think most people would enjoy driving against more, varied people ?
Now im quite lucky in the fact i do have a bit of spare cash to spend on buggies, but i havent done two classes at our regionals this year for precisely that reason - i dont like the idea of paying 20 quid for two classes ! Call me tight if you want, but its the principal of the thing

Im doing both at Caldicot because its my club, but i wont at the others. Lower it down a wee bit, not too much though, or offer 1/2 cost second class, and i bet you would have more people racing 2 classes....
Just my thoughts