Paying $90 for new RAM tubes is ridiculous when these are likely Sovtek or EH "hand-picked" tubes. You can buy 6 or 7 of these at places such as here
for $90 and surely 4 will be fine for your PH-5. I'd bet that all would be as good as the RAM or ARC tubes. Call this dealer for advice and see if he is will to let you try various tubes. As you can see, there are many brands stocked here.
Since the PH5 uses a solid-state input gain stage, the tubes in this unit are not used in a high-gain MC stage and thus you DO NOT NEED ultra-low-noise phono stage tubes that often cost a significant premium more.
You can get killer deals on several other tubes from many online-tube dealers that will take your unit's performance beyond what even the people at ARC have likely never heard it sound. As for paying $35 for the tubes at ARC, that too is equally ridiculous. There is no black magic that ARC or any other electronics manufacturer does to these mediocre-performing russian tubes.
You invested in a tube product. If $50-100 is your budget, then stick with Sovtek or EH for the quad. If you want much higher performance, do your homework here first. Read through the forums here on suggested tube dealers and other ideas for 6DJ8, 6922, 7308 tubes. If you are truly willing to spend $400 for a quad of tubes, look for advice on Amperex 6922 pinched waist or Valvo to start. Telefunken 6DJ8 can be awesome too as well as the Amperex and Mullard 6922.