Could you clarify what you mean my PA being a tax deed? Investor and agent from PA, I might be able to offer some insight but not sure what you mean.
Also, as far as I know taxes are a county thing, so it will vary from county to county how the sales are handled. Also known as a sheriffs sale.
Furthermore, and most importantly, you could very well purchase a home at a "tax sale" for the balance due, let's call it $10,000, but any other liens on the property will come along with it. So great, you bought a $100,000 house for $10k, but you also inherited the $120,000 mortgage that comes along with it. There might be online resources to use in order to research property information prior to a sale. As an agent I have access to most mortgage information, but iv been told a good title company will be your best source for finding complete and accurate information on your subject properties.
Im sure there are certainly opportunities to be had, but this seems like a space you need to be very knowledgeable and or experienced in to take advantage of. Personally I would find it easier to use these lists as a means of finding motivated sellers, and approaching them directly to try to purchase prior to it going to auction.
I am by no means an expert in this space, but this is my understanding of the process. Hopefully someone with experience with tax sales will chime in and provide more detailed info, I'm curious to hear how close or far away my view is from the truth. Best of luck if you decide to give it a try.