As sheep farmers across the land tighten their belts, Mr Beavan's warning is prophetic. A year ago, his lambs sold for around pounds 55 a head. In Abergavenny market this week, prices rarely reached pounds 38.
More than 1,000 ewes and some 80 cattle share the 350 acres, a stone's throw from Offa's Dyke, the earthwork built in the 8th century by the King of Mercia to guard against the Welsh.
Not long ago, Mr Beavan, 62, ran 150 cattle but he sold nearly half to raise some cash.
Sporting an Ernest Hemingway beard and possessed of a steely determination, he has been farming all his life. His sons, Huw, 33, and Jim, 30, work with him while his wife, Anne, presides over Great Trerhew farm, a solid stone building dating from the 16th century.
The family typifies the cornerstone of Britain's rural life, struggling in what some fear may be a crisis too far.
Sides of bacon in muslin bags hang in the beamed kitchen. A Welsh dresser, a piano and arrays of shining brass stand sentinel near a table over which the arithmetic of a business hit by the BSE crisis and low livestock prices is discussed.
Co-operation is the order of the day. Earlier this week, Huw and Jim were out helping at a turkey farm. "They do a bit of contract shearing, and they'll turn their hands to anything," Mrs Beavan says.
In uncertain times, income is derived from whatever source presents itself. Sweetbreads from castrated cattle are sold to the famous Walnut Tree Inn five miles down the road.
Mr Beavan reckons that live lamb earns about 85p per kilo at market. At Abergavenny's Tesco supermarket, a short stroll from the pens, lamb chops were on sale this week at pounds 10.29 per kilo. Add in cheap antipodean imports and it is not hard to understand farmers' worries.
Mr Beavan uses 30 acres of good Monmouthshire soil to grow barley and oats to feed to his stock - a useful and ecologically friendly input at a time when costs had to be tightly controlled.
"You've got to remember that there's four legs to a sheep but on the butcher's slab there are really only two - the best cuts come from the hind quarters," Mr Beavan said as a tractor carrying fodder for the ewes ground up the mountainside.
Looking east, it is possible to make out the line of Offa's Dyke. The Beavan land touches White Castle, an ancient Norman fortress employed for the defence against all comers. The summer tourists are long gone but on a misty December day its defensive position is clear to see.
Today, the defence of a way of life and an important industry resides in another "White" - Whitehall. A little help from Strasbourg wouldn't come amiss on the slopes of Skirryd, either.Reuse content