I have one of these, too. I even made a small picture series of my setup. You don't have to buy minis either. Just print them, using some graphic on the internet :-D
To be honest I though you were already using a re-usable map. Designing them in gimp/photoshop/mspaint/whatever every time and printing them, or drawing them on big graph-paper is a huge waste of time imo.

Maps don't have be be pretty at all - don't overdo it.
I remember some of my DnD maps very fondly. The fighting arena my players made some money it – it was a glorious 8 inch circle, with two entrances top, and bottom.
Roll20 basically is one of these maps, btw. I recorded a time lapse creating some of my Shadowrun maps. Simple maps like these are WAY more than enough.