Graveblade Marauder and Ukud Cobra are very good with fight effects
The Base Set is the foundation of the Pokmon TCG hobby, but not all Base Set cards are created equal
It is common for a description to sound like a high-rarity version, but upon looking at the photo, it is actually a different specification
So even if your rats are attacking as 6/1 or 10/10 monsters, they remain 2/1 creatures until they enter the battlefield
If you can find one or two at a garage sale, or a stash in someones attic, it can amount to major profit
A lot of balance and care goes into choosing the cost of a card, more than I can express here, but looking for similar effects on existing Magic cards can give you an idea of a fair costfor example, a ramp spell that puts two lands into play ought to cost 4 mana, per Explosive Vegetation