The price ratios are approx. 1:11.

Just for the sake of argument, let us assume that the non-ISP cost $5 and the ISp cost $55 (ridiculous, find another distributor, there are Atmel, Philips and Maxim ISP parts plus many others, you do not have to stich with a given brand).

Now you have spent $25 on components for the programmer so you would be out $25 using the ISP part.

You have, based on the posts et al probably spent 50 hours building it and trying to make it work.

Is your time only worth $0.50 per hour?

Erik