So, with the starting market rate set at 125 and increasing 1 every time you buy 100 you can buy 1300 wood and save VS with each purchase. The total number of VS you save for buying those 1300 wood? Approximately 132 VS total! Your first purchase at 125 saved you 18.84 VS and your last one at 137 saved you 1.449 VS. Not much for depleting your gold mine by 1703 gold for 1300 wood, is it?
Well, lets see how it looks with the Advanced Market. The Advanced Market card sets the buy rate to 80% of whatever it is when the card is played. If you play it before you buy anything, it gets set to 100. That means our first purchase would save us 55.072 VS and we can purchase up to 3800 wood at a VS profit.
The total profit for buying 3800 wood from rates 100 to 137 is ~1074 VS. Now we're talking! But was the card worth it compared to another card? It gained us 942 VS which makes it equivalent to a 471 wood card if there were such a thing. Not bad for an Age 1 card but stil not all that and a bag of delicious potato chips.
Just for fun, let's try this a third way. We'll buy wood without the card up to 137 and then play the card and buy it up to 137 again. If we play the card when the rate is 137 it resets it to 110. Now if we buy from 110 up to 137 we buy 2800 wood for a VS profit of ~588 VS. Combined with our initial figures from above we see that we bought 4100 wood and our net VS profit is 720 VS. We bought 300 more wood than in our second example, but gained 354 less VS. Clearly we can conclude that sending the Advanced Market card before doing any purchasing is the way to maximize our VS profit.
There are a couple more things to consider here. First is that once you've played the Advanced Market card, you've got it if you need it. For instance if all your hunters are garrisoned and you need 400 food for CM, you'll save 100 gold buying that 400 food.
The second thing to consider is that in order to buy 3800 wood in order to realize that maximum ~1074 VS profit, you have to mine 4503 gold to do it. That's 2 mines empty and a 3rd a quarter gone. Considering that Dutch players have to spend gold for everything including using the toilet, this may not be wise. The exception would be if you were doing some strategy involving taking early map control and stripping all the mines clean so that your enemy couldn't have them.
CONCLUSSIONS: Buying wood with mined gold will hardly be worth it without the AM card and will suck your mine dry. In most cases I would recommend just cutting the wood. It's true that buying 400w for a bank in Discovery would save ~67 VS which is a lot in the early going, but the fact that you had to use 100 wood for the market and then the VS to build it negates most of that.
Buying wood with the AM card is much more worth it, but it's still not great enough to make sending the card worth it in most cases. By the time you've mined enough gold to get the max payoff, the 3 villager card could have gained about the same amount of VS and it doesn't have a max.
If, however, you are using a strip-mine the map strategy you probably do want to play the AM card as you are going to end up doing a lot of purchasing since almost all of your villies are on gold. In this case, playing it before doing any purchasing at all is the most profitable.