You could get a Minolta Flashmeter III for around $100. I use one, and find it's pretty reliable. It can take incident readings (ambient or flash) or you could add a 5-degree finder for reflected readings, and there are other accessories that may be of interest, like a flat diffuser for copy work or for determining contrast ratio with multi-light setups and a booster unit for groundglass or through the viewfinder readings. All Minolta Flashmeters and Autometers from the Flashmeter III to the Flashmeter V use the same accessories.