I looked on ebay. $11 for 4.5g. Not sure if that's the size of the regular tiny bottle they sometimes give u. How do they expect you to lube your shimano parts if they don't provide easy ways to access it?
Yeah, I use both grease and oil...you can put a little on the main gear through the access port and oil the worm gear
+1 If you want to do it right I wouldnt even bother using the port and would go ahead and disassemble the reel anyways. Unless you are in a pinch for time but otherwise your just adding clean grease to dirty grease and if you keep adding it, it will eventually be too much grease and will effect the performance of the reel. I use Quantum hot sauce, and Boca's Lightning oil and have never had an issue with either.