There are some very inexpensive ones on eBay that use two AAA batteries for as little as $3.00 each. Search 532nm laser pointers. These little ones are not focusable, but they are mostly 50 mW or less. I wouldn't pay more than $5.00 for one, though. So, you might have to search.
here is what you do..
the mag glass upper right corner is the search--I put 'wanted green laser 50mW'
& here is what I (and you )got back ..take your pic , friend.
OK you are helped--ready to pay that back? good(nothing is free here)
PLZ 1) finish your personal profile.. include something about where you live. (place in 'about')
THEN compose a nice intro and find the welcome/newcomers section
Unless you are not a 'new member' .
post that and btw it is a good idea to put something about you location INTO YOUR 'INTRO THREAD' TITLE.. 'Like hello from NYC' etc why will be clear to you after you have been here a while..
WE are happy to answer questions (but NEW ones) anyone has..
Its up to you to do the searching... then, if nothing found--make a thread for your question in the correct section..did you read all in the BS&T.SECTION??? lots for sale... always a better idea to buy local (from a member)..BUT you need to read and ask... not my job..
enjoy your stay.. hak