I don't know may be New Zealand has own supply of ACN, but here in US price per case ranges from $1000 to $1900 (4/4) with the back order for 2-6 months, this is almost $100/L. ... Almost every other customers asks us to reduce consumption/price impact of ACN, so I am not buying "cost of ACN is a relatively small part of the total cost of an analysis".
If you have an instrument which pumps 80% ACN with 1 ml/min (typical HILIC) then average lab which uses the instrument 150 days a week, 10 h per day will "waste" extra: 0.8x60x10x20x150x75/1000=$5,400...and some labs are doing it 300 days 20 h a day or $21,600/year for busy labs. This is not considering impact on environment and cost of waste disposal.
I don't want to get into a dispute, and I agree that conservation is sensible. I am not sure about capital expenditure based on a price spikes - how many companies sold corporate cars and bought more fuel-efficient ones last year solely based on projected fuel savings?. The current price of gasoline is going to play havoc with projected savings
I've just purchased some CH3CN at the quoted $NZ price from a global supplier. Sigma Aldrich are also offering gradient grade here at US$57/litre. The US$ "cost" has increased by 11% as the US$ has depreciated against the other currencies over the last 2 weeks, which may partially explain some of the difference.
As I said in the other Acetonitrile Shortage thread, if a supplier is opportunity costing, look elsewhere. I also performed a similar calculation to yours to refute a claim that the capital cost of an lower usage instrument could be recovered by solvent savings in a year. at $100$/L 10 x 150 x 60 x 0.8 = $7,200. Assume new system would yield 20% of consumption then $5,760. Waste disposal cost is about $0.50/L, so add another $34 saving.
Here, a UPLC starts at around US$65,000, laboratory staff are paid around US$30,000 pa. So, one HPLC's depreciation alone ( 8 years ) is going to be much more than the saving. Labour will be several times more ( depending on labour content / instrument ).
Here, many research organisations here have overheads that are multiples of wages ( 2 - 3 times is typical ). Increased acetonitrile cost has to be factored into costs, but where to expend capital to maximise returns will vary according to company.
If acetonitrile is critical to your business, it's relatively easy to arrange forward orders from most major suppliers, including purchasing in bulk at lower prices, and a good relationship with your supplier may minimise opportunity costing.
If you need to replace old equipment then it's obviously sensible to look at the potential future savings, but I suspect that acetonitrile price will follow supply and demand trends and continue to decrease as new CH3CN suppliers take the opportunity to make some serious money.
It's also a great time for instrument, and column

, suppliers to encourage users to downsize - the economics have never been better - shame about the recession though....
Please keep having fun,
Bruce Hamilton