I dislike this whole idea. Trading restrictions (value and levels), levels, how levels are advanced, all of it.
Levels: L1s can't trade with other L1s. Wanna trade your Drana, Liberator of Malakir for 2x Cinder Glade? Tough. As a user with low feedback who loves janky rares, I'm mostly interested in low-value (which carry an inherently lower risk) trades. This rule would seriously limit my ability to trade random little junks for other random little junks.
Advancing: Having advancement be tied to the value of cards traded seems bad. I'm far more likely to be comfortable trading with a dude who has made a dozen $10-15 trades than one who traded away a playset of Aether Vials and a pair of shocks. A "number of trades or $xx, whichever comes first" threshold makes far more sense.
Value Limits: This feels downright hostile to new users. I would be disinclined to trade a Magus of the Moon to a Canadian L4 since his $30 price tag would eat up the majority of my L1 limit for a full month. Did I get lucky and pull an Expedition at draft? Looks like I can't trade it locally or here. Sure, I could pay money to get the restriction lifted, but that feels an awful lot like bullying.
Foreign Users: I don't live in the US. I have no problem trading worldwide since postage is 0.90€, but all trades to North America take about a month to complete (send first, 2 weeks until receipt, 2 weeks until my cards arrive). It took a while to cross the 5-Trade threshold, and that was without additional limits being set on my ability to trade. While I heartily recommend Deckbox to my buddies, my recommendation would change to "It's nice for inventory management, but you really have to work to get anything out of the trading system" under the suggested changes.