A new Spaceprobe + Edge-On eye piece would be $410. $275 for both is enough of a discount for me personally.
The 130mm Newtonian will provide a noticeable increase in light grasp over your refractors. You'll be able to see more, especially if you can travel to a dark sky. I think you'll be pleased with that.
As you said, you'll have to learn collimation. It isn't hard, but it does take practice, and it's much easier to learn if you have someone who can teach you in person. You'll also have to get used to putting your scope outside for a while before you want to observe to allow the mirrors to reach ambient temperature.
The weakest link in the package, in my opinion, is the EQ-2 mount. The tripod is pretty weak and does not support the mount and scope well. The mount itself is very basic, which is not inherently a bad thing. At least they have provided a dovetail bar and tube rings. The 4" Maksutov Santa brought as my family's first scope attached to the EQ-2 mount with a 1/4" screw and a photo tripod-type mounting pad. No matter how much I tightened the screw, the scope always swiveled on the mount.
Larger Newtonians can be a pain when mounted on an equatorial mount. The eye piece will often be in an uncomfortable orientation. The classic solution is to have rotating rings of some kind (the scope you've pictured doesn't have those). "Real" rotating rings are expensive, but you can get the same functionality by adding one more ring (you can buy a pair from Orion, not single rings). The third ring gets installed between the focuser and the front mounting ring. The two mounting rings are left loose to allow the scope to rotate. The new third ring and the front ring slide against each other keeping the scope steady while you rotate it. I've got an 8" Newtonian I use at the house with this set-up, it works well.
If you decide to buy the SpaceProbe, I think you'll be looking for a new mount soon anyway, so the deficiencies of the EQ-2 may not be that big a deal. A small manual alt-az mount would be a good choice to the SpaceProbe. Something like the Orion Versa-Go, or a Twilight mount...
John Miele makes valid points. Dobsonians are definitely easier to observe with than an equatorially mounted Newtonian without rotating rings. However, an Orion (or SkyWatcher, Explore Scientific, etc) 6" or 8" Dobsonian will be bulkier and take more room to store than the SpaceProbe. If storage space is scarce in your house, you should consider that, too. My son and I used an Orion 6" Dobsonian similar to the scope shown in the link John Miele provides. We had a lot of fun with it, it's a good scope. It took up a lot of space in his room, though, and wouldn't fit in his (admittedly tiny) closet.
Edited by macdonjh, 16 July 2020 - 08:38 AM.