Soft sugar maple is a contradiction in terms. It cannot be both
Your probably going to have to look at it to know what he has as sugar maple and silver maple are not the same thing . Also most of what we think of as hard maple is in fact not classified as hard maple but soft maple . suger Maple is not a soft maple .
At one time I worked at a company which made church furniture . Things like pulpits were made from what was ordered as sugar maple. It has little to no figure as we would call it and was as white as paper . It was also so hard that we had to replace the planner blades constantly . Also our big powered time saver which ran multiple grits of sanding paper would literally destroy the paper in a couple passes . Also if you try to work it down to fast it will easily scorch and burn the paper up .
i also spent years in the flooring industry. suger maple is very hard as is black maple. in some cases you can not even nail through it and have to pre drill or it will split or completely turn a nail and jam up you floor hammer . they also look alot diffrent then the softer maples .
To say the wood was not hard would be an understatement.
I also buy my planks through a local hard wood dealership
If you go in and ask for hard maple with figure , they will tell you they have non or that its very uncommon . But they will let you dig through it . They have two areas . One labeled hard maple and one labeled soft maple
Those areas are then broke up into different maples . In the hard maple area you will find rock maple /sugar maple and Black maple . those run in the 9-12.00 bdft . So a plank thats of 12 quarter can run you 450-600 depending on the board , if its plank saw or 1/4 sawn
Under soft maple they have ,the choice of Big leaf maple , red maple , silver maple and striped maple.
those run from 7.50-9.00 a bdft so around 250-350 depending again on the board and if it slab or 1/4 sawn
So what im getting at is the person may be telling you that the plank he has is one of the classified soft maple verities . most likly silver maple as thats what alot of time people mistake as suger maple .As such you would be best to have some idea of what your looking at when you go look at it
Here is a link on maple , its hardness and its classification. Also information on how to tell the differences
http://www.wood-database.com/wood-articles/differences-between-hard-maple-and-soft-maple/