Based on the latest market prices tracked on TCG Stacked, Sam, Loyal Attendant is worth about $2.53 USD for a regular copy and $2.73 USD for a foil copy
Borderless Anowon, the Ruin Thief - photo in comments (foil peel alter, not a proxy and no printing involved) My Rogue deck from around when Lorwyn block was legal still brings back fond memories of kitchen table Magic
Latias ex feels like a very fun attacker to build a deck around, assuming you have some kind of solid support to accelerate energy onto it
Fortunately, combat tricks deal with them reasonably well, as does most removal
Only spells (and their copies) and abilities (and their copies) can be on the stack
This card's restricted Vintage status, compared to Wheel of Fate, is only because of the variety of combos discarding and drawing without shuffling enables