Measuring lead content in pewter I've bought pewter at the thrift store and I want to try casting metal. This pewter may contain toxic metals. A ready-made testing kit I've found cost €25 for each sample. 

In comparison pewter of know origin (98% tin/2% antimony) costs €40 per kg,
pewter from the thrift store is €4 per kg. If possible I want to test the pewter before buying.

Is there an easy way to measure the lead content of a pewter sample? 

I'm not a chemist but do have a basic understanding of chemistry.
I've calculated the density of the sample to be: $8.55~g~cm^{3} ± 0.5~g~cm^{3}$.
You are likely looking for trace levels, so I do not suggest any at home kit. At best, is it colorimetric and sensitive to interferences. 
If you really want to know, find an environmental lab and ask them to run ICP-MS to determine the lead content. Atomic absorption spectroscopy would be the second best method.