Don't feel bad; my collection cost me thousands and is now worth more than triple what I originally paid for it. It took me two years to amass it, given exactly how rare many of the vintage V-Pets are nowadays(especially in any servicable condition). Many of the ones I enjoy most are newer(the Minis, Xros Mini, and the iC20X, specifically), so you're not entirely out of options.
However, Pendulum X, Originals, and Original Pendulums will run you EXTREME amounts of money, NIB and even just mint/used condition now. Even four years ago, some of my Pendulums cost more than 80 USD NIB, and one particularly rare version(a Pendulum 5.5) cost $120. If you want a Pendulum Progress 3.0, you're looking at an absolutely nauseating sum of money NIB; they can be as high as $200.
My Original v1 will always hold the most precious place in my heart, even if I run my Minis instead of it(largely out of fear of breaking/damaging it, by now, as it is still in very mint condition even after 15 years of not inconsequential use), however.
Your first Digimon v-pet will always be significant to you, and in choosing the iC20X, you have made a choice I can promise will satisfy you. I personally wrote the guide for the minigames on that version that is hosted on File Island(and am credited on it as Orochistorm, my name on WtW), and it really is just one of my favorite devices, both aesthetically and in roster, function, and managability.
By the way, I decided to go through mine and take full inventory of everything I own. Here is my full collection, all of which have been opened and used, but are mint, and most of which still have their original packaging:
V-Pet Collection:
Bandai Japan V-Pets:
-Original v1 x1(Rare Red-and-Gray version)
-Original v4 x3(2 Red, 1 D1 Grand Prix Silver)
-Original v5 x1
-Pendulum 1.0 x1
-Pendulum 2.0 x1
-Pendulum 2.5 x1
-Pendulum 4.5 x1
-Pendulum 5.0 x1
-Pendulum 5.5 x1
-Pendulum Progress 1.0 x1
-Pendulum X 1.0 x1
-Pendulum X 1.5 x1
-Pendulum X 2.0 x1
-Digimon Accelerator Justice Genome x1
-Digimon Accelerator Nature Genome x1
-Digimon Mini v1 x2
-Digimon Mini v2 x3
-Digimon Mini v3 x1
-Digimon iC 20X x1
-Digimon Twin L x2 (1 Normal, 1 L&R Silver Twin Set)
-Digimon Twin R x2 (1 Normal, 1 L&R Silver Twin Set)
-Xros Wars Mini Blue Flare x1
Bandai Japan Digivices/Adventure Pets:
-Season 1 JP Digivice x1(Blue)
-D-3 v1 x1
-D-3 v3 x2
-Ultimate D-Ark GALLANTMON CRIMSON MODE Ver. x1
-Xros Loader Blue Flare ver x1
Bandai Asia V-Pets:
-D-Cyber 2.0
Bandai Asia Digivices/Adventure Pets:
-Digimon NEO v1
Bandai America V-Pets:
-Original v1 x2(1 Teal, 1 Navy Blue)
Bandai America Digivices/Adventure Pets:
D-3 x2
D-Tector x1