Can someone please explain to me...

[TheIronHorse4]

Yea not really. If you want a better representation of what a card is worth, check current/completed auction listings on ebay.

[agold2121]

Agreed...best way to do it. Best indication of real market value is ebay.

[Goose97]

I guess this all comes back to BV not actually meaning a thing.

Yup!

Only if you were to use it. Use it only for trading, but even in that case allow for some leeway.

[agold2121]

I use it for trading but only cuz that seems to be the accepted medium around here. Makes absolutely no sense to me...but whatever.

[reoddai]

From the beckett book itself (this is a quote and a small portion, so liability wise, no problem):

"The LO and HI columns reflect current retail selling ranges. The HI column generally represents full retail selling price. the LO column generally represents the lowest price one could expect to find with extensive shopping."

As for the GEM 10 comment you made, theoretically, there is not such thing as a "perfect" card. There's always a small flaw which results in making it Mint instead of Gem Mint.

For buyers, since the quality of a card is so subjective, there may be a big selling difference between two Mint cards and two Ex cards. That being said, Beckett also provides a "rule of thumb" multiplier for modern day cards (1990-present)
Mt - 100%-125% of BV
NrMt-Mt - 100% of BV
NrMt - 30-50% of BV
Ex-Mt - 20-30% of BV
Ex - 10-20% of BV
Vg - 5-10% of BV
G/F/P - 5% of BV

A key note is what many people have already said. The accuracy of BV lately has been very poor. That being said, Beckett is often consistently wrong. A card that has a BV of 8 is usually equal to another card with a BV of 8, 90-95% of the time and can often help out people making trades if a trader is unfamiliar with the value of the cards they have.

Hope this helps.
Cheers,
reoddai

Hope this helps

[Marko]

i see the LO as an indication of the sell value

and the HI as an indication of the trade value