First, please note that we do not give legal advice on this site. Here is some general information about gambling laws in Pennsylvania, but if you are planning to do something and want to know whether it is legal, you will have to hire a lawyer.
I believe this sort of thing would be a lottery under Pennsylvania law, which is prohibited in Consolidated Statutes Title 18 ยง 5512:
(a) Status of activity.--All unlawful lotteries or numbers
games are hereby declared to be common nuisances. Every transfer
of property which shall be in pursuance of any unlawful lottery
or numbers game is hereby declared to be invalid and void.
(b) Offense defined.--A person is guilty of a misdemeanor of
the first degree if he:
- sets up, or maintains, any lottery or numbers game;
- manufactures or prints, or sells, exposes for sale
or has in his possession with intent to sell any unlawful
lottery or numbers ticket or share, or any writing, token or
other device purporting or intending to entitle the holder or
bearer, or any other person, to any prize to be drawn or
obtained in any lottery, or numbers game; or
- publishes any advertisement of any lottery or
numbers game.
It doesn't appear to matter whether you are making a profit or not.
A first degree misdemeanor is punishable by a fine of up to $10,000 and up to five years imprisonment.
There is a process to get a license or permit to conduct "small games of chance", which includes raffles, but it generally has to be organized by a recognized non-profit organization for charitable purposes. Additional permits are needed if the prize is to exceed $2000. (There is also a provision for "tavern games", which can be run by a bar or similar business, but in this case the prizes are limited to $2000 with no exceptions.) Here is a summary from the state Department of Revenue, which also has a good general overview of gambling laws.