We have had 3 long successful term Houseboys and while every situation and agreement is different I pay what the national average is listed for an Au Pair. Here in the US it's roughly $200 per week, then give them room/board and cover any travel that they do with us or meals out. We do not cover phone expenses or auto expenses. Any food request we are usually happy to accommodate.
When meeting someone for the first time we will not pay any money up front but we will reimburse them for travel to us. We do this because of all of the scammers.
ABSOLUTELY NO MONEY BEFORE WE MEET THEM! I tell everyone one of them this upfront and at some point most of them ask for money. They love to ask to pay for a ticket then send them money for incidentals like meals even when they are only an hour away. It's all a big scam and this site in particular has gotten very very bad. There is a lack of Moderation.
Good Luck