Complex sentence: Estimated value-$50--70 million for new system; alternately a second-hand system might be obtained as a donation by the United States, in which case only the VAT cost will be incurred.
Split into simpler sentences: Estimated value-$50--70 million for new system. Alternately a second-hand system might be obtained as a donation by the United States, in which case only the VAT cost will be incurred.