Looks like PA will make it, but it's going to be close. I'm estimating late afternoon on the 3rd, just hours prior to draw time, they'll sell out.
Other states, such as Delaware, have offered $10 raffle tickets, and struggled to sell them all. Ohio has extended their sales window and still might not make it. What makes the difference, beyond just population alone, is the number of readily accessible lottery terminals and player loyalty. PA has a very strong lottery - many states aren't as fortunate, and struggle with their lottery operations; some outsource it, but often that doesn't help / makes matters worse. If players don't feel valued, they won't play as much - loyalty really matters, especially when there are so many other gaming choices out there.
As for the difficulty of selling raffle tickets, the vast majority of lottery players don't really understand much about the games they play - it's among the main reasons for the popularity of instant tickets ... just scratch and cash. Fast with little to no thought required - heck, some just buy whatever is in the machine at the price-point they desire, and then scan it to see if it's a winner...
This extends to numbers games, and California is a prime example of it in action. Take a look at the number of Powerball and Mega Millions lottery tickets sold there, which is huge, and then take a look at the number of tickets sold for their in-state Pick 3 and Pick 4 games - relatively little considering the population of the state. PA Lottery net revenue is only somewhat less than that of the California Lottery despite Pennsylvania having 1/3 the population.
Most lottery players, even more so in other states, play the familiar numbers games (in state lotto, Powerball, and Mega Millions) that have relatively low price points of $2 or less. Raffle seems way too expensive and complicated - ignorance is bliss. Most players don't want anything too different despite many saying they do; $20 raffle tickets is out of the comfort zone for many.
It's the same issue one sees at a casino - many players will gravitate towards the quarter and less slots, especially the penny ones - sure, it seems like a value, but the penny slots are about the worst payout machines one will encounter at a casino. Savvy slot players on a limited budget will focus their play on the highest denomination that provides them reasonable length play - for many that would be quarters to $5 machines; higher denomination machines can actually be both a better value and cheaper to play, such as a typical max bet 3 coins quarter slot (75 cents total) verses a penny machine with 225 coin ($2.25) max bet.
States with smaller populations and/or less player loyalty would do better to offer a very limited raffle, such as 10,000 to 100,000 tickets max. The price-point really doesn't matter much; $10, $20, or heck even $50-$100. The relatively small group of diehard players will buy raffle tickets regardless of the price, if the odds and/or payout structure is better than the typical numbers game offerings.