Cycling Jedis, please help this young Padawan choose a bike!

Apologies in advance if this is a shit question but I need your help! I am on the market to buy a bike, but I'm a tightass and only really want to spend a couple hundred bucks if I can help it.

A bit about me: I live in Melbourne, Australia. About 180cm tall and weigh about 85kg OK JUST READ THE FAQS AND APPARENTLY THIS DOESN'T HELP. Intending to use this bike primarily on bike paths to and from my girlfriend's place (about 10km away). Not sure what else you need to know about me but if you need any more info for your assessment then just let me know.

I am currently looking at second hand bikes on Gumtree. Here are a few:

• Schwinn vintage 7 speed $220 negotiable
• Apollo men's 10 speed $270
• Shimano full Ultegra groupset $250 negotiable
• Some generic 14 speed hybrid $150
• GIANT something unspecified painted matte black because the previous owner is ridiculous. $150

OK so these are my current options. I likely have some room to haggle in terms of the prices but mostly I'm looking for something that's a good fit. Feel free to suggest other bikes if you think they're a better fit for me.